-LRB- CNN -RRB- -- A man believed to have been exposed to the deadly poison ricin in a hotel room in Las Vegas , Nevada , is out of his coma and is being questioned by authorities , FBI Special Agent David Staretz said Friday .

Ricin , guns and an `` anarchist-type textbook '' were found in a room in this Las Vegas hotel , police say .

Staretz would not comment further on Roger Bergendorff , 57 , who authorities said was taken to a hospital February 14 after complaining of breathing difficulties .

He is listed in critical condition , said Naomi Jones , spokeswoman for Spring Valley Hospital Medical Center in Las Vegas .

Bergendorff , an artist who neighbors said had lived in his cousin 's basement before moving to Las Vegas , was exposed to the poison in a Las Vegas extended-stay hotel , a law enforcement official said .

The Riverton , Utah , home where Bergendorff previously lived belongs to Thomas Tholen , who along with his wife and daughter tested negative for ricin , according to authorities . That home and three storage areas in nearby West Jordan , Utah , were searched for ricin earlier this month and declared safe by authorities .

A relative who went to Bergendorff 's hotel room after he was sent to the hospital found the substance and alerted police February 27 .

Ricin is a poison that can be made from waste left over after processing castor beans , according to the Centers for Disease Control and Prevention . It can come in the form of a mist or pellet and can be dissolved in water or weak acid , the agency said . E-mail to a friend

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Roger Bergendorff thought exposed to ricin in Nevada hotel room

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Bergendorff , in coma since February , awake and being questioned

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Ricin is poison that can be made from waste after processing castor beans